The book is about people who put stuff inside their head.
They devour old films, new films, music, books, random conversations... First they consume, and then they steal what they have consumed.
If you want to increase the quality of your work – your output – you must increase the level of your inputs. Your input is knowledge. The more pieces of knowledge you have at your disposal, the greater the opportunity for explosive connections and the better ideas you will create. It is that simple.
I've stolen the last two paragraphs from his book. Practice what you preach. You the real mvp Harry.